After a court order voided an agreement the City of Miami made to host an auto race in April, Raceworks, the producer, has announced plans to reschedule the event to October.

Originally set for the first weekend of April, the Grand Prix of the Americas is now planned for Oct. 4-6, said architect and developer Willy Bermello and attorney Peter Yanowitch, principals of Raceworks.

They denied the rescheduling was related to Monday’s court ruling and said roadwork to prepare for the downtown race will continue.

The 11th Judicial Circuit voided the Miami deal because the city did not follow competitive bidding procedures when awarding Raceworks a 25-year license to hold the event in Bayfront Park and did not make the agreement revocable, said Jorge Luis Lopez with the law firm Steel Hector & Davis representing the Homestead-Miami Speedway.

Speedway officials sued the city five months ago to stop the race, saying it would steer business away from their track and because they were not given a chance to bid to host the event.

The court order calls for the city to give the Homestead track operators and others an opportunity to bid and be "equally considered before the city enters into any lease or any contract for use of the city’s waterfront property for motor car races," according to the 15-page court document.

City Manager Carlos Gimenez said Tuesday the city will hold a road race downtown in October no matter what it takes.

"The race will happen because it has the political support," he said.

Mr. Bermello said Tuesday that Raceworks was moving forward with plans despite the court decision. Mr. Bermello said he trusted the city would rewrite the agreement to make it legal.

He also said the event was being rescheduled to allow Raceworks, already bringing the American Le Mans Series to Miami, extra time to recruit the Championship Auto Racing Teams, or CART, to participate as well.

It would be the first time ever in the US that two premier road racing series take place together, said Scott Atherton, president and CEO of Panoz Motor Sports Group, which represents the Le Mans.

Mr. Atherton said the rights his company gave Raceworks to bring the Le Mans to Miami were contingent on the promoter being able to hold the race. Aware of the court order, he said he was encouraged by Miami Mayor Manny Diaz’ assurance that the race would happen.

"When I hear the mayor proclaim the race will go on, I am going to side with Raceworks," Mr. Atherton said. "The mayor’s endorsement is the most significant signal."

He said Mr. Bermello and Mr. Yanowitch told him they were on top of the situation and, although the court ruling was serious, they could solve it.

The promoter, which pulled city permits to do $1.1 million in road upgrades near Bayfront Park and Biscayne Boulevard, would expand the planned racetrack to accommodate both races, Mr. Bermello said.

But Mr. Lopez said race-related roadwork might not be able to continue because Monday’s court decision made permits ingrained in the 25-year license invalid. He said the city should stop the street repairs.

City Attorney Alex Vilarello was not available for comment on Tuesday.

"They are doing it for reasons I cannot understand," Mr. Lopez said. "The promoter and the city are not following a court order."